Apparatus for drilling oil wells



Patented .im 26, 1926.

UNITED] STA-rss uns r.

*"PATENrj eFFjlc-E.

FISHER, OF BABTLESVILL, OKLAHOMA, ASSIGNOR TO DOHERTY RESEARCH COMPANY, F NEW YORK, N. Y., ACOREQBATION OF DELAWARE.

, x APPARATUS FOR DRILLING nppucmqn'mea :une 30,1922; Semi ilo. 572,056.

To all whom z't may comem: y

- Beit known that I JAMES P. FISHER, a citizen of the .United i States of America, residing at Bartlesville, in the county of Washington, State, of Oklahoma, have invented certain new and useful Improvements in Apparatus for Drilling OilWells;

v and I do hereby declare the following to be al full, clear, and exact description of the invention, Vsuch as will enable others skilled in the 4art to which it appertains to make and use the same.

This invention relates to .apparatus for Y drilling wells, and more particularly to an apparatusfor drilling oil wells, whereby the time required for drilling'may be greatly reduced, and whereby they time during drill-bit there is a resultant dash pot action which the drill is in continuous use may Ibe greatly increased.

The present invention is based upon the discovery that. by setting up a local circulation of water near the bottom of a well dur ing the drilling operation, and by the use of a special form of drill, the mudding up of the drill-bit may be "prevented, and the drilling operation carried on at a much faster rate'.

One of the main diHcu-lties encountered in drilling operations is due tothe mudding up or formation ofmud pads on the drillbit, which necessitates the frequent halting of drilling operations for the cleaning of the drill-bit. Due to this mudding up of the during the reciprocation of the drill, which not only increases the power required for operating the drill, but also renders the cutting stroke ineffective, because of the decrease in the force of the blow given by the drill-bit. Furthermore, the cutting action of the drill is greatly hindered by the presenceof mud around the cutting edges of the bit.

It has been attempted by various means to overcome the diflicultiesin drilling operations due to the above causes, Abut thus far only partial success has been attained. The wells which are now drilled -for the production of oil commonly attain a depth of Li000 feet or more, whereas in the early development of the oil industry wells were drilled generally to a depth of only`a Afew hundred feet at the most. One form of a drill which was developed for the drilling of Shallow wells, but which proved to be in- I'off sandand heavier particles 'in the water effective for drilling deep wells, employed a hollow stem and bit in the drillin operation,and water was umped down t rough the stem-toy assist in ringing up mud and drill cuttings to the surface of the wells. This drill was ineicient when applied to the drilling of deep wells for the following reasons: v,

4(l) In' umpingywater from the surface of the We to the bottom thereof of the drill cuttings, sand, etc. were not carried to the surface by the return current of water, and only thelclay and lighter d irt particles were washed to the surface.

(2) A second defect of the drill, when applied to the drilling of deep wells was due to the fact that clean Water would not hold sand and drill-cuttings in suspension and consequently there resulted an accumulation v which greatly increased the..v .power necessary to operate the drill, and also rendered the usual hailing operation necessary because the water would not bring .the drilled material to the surface.` l

l (3) Another defect which was perhaps of an even more serious nature than those vabove mentioned was the fact that in 'circuhydrostatic pressure, and under this condition there would frequently be no fiow of gas or oil even though it was present, and

the pay strata would be drilled through vwithout any kindication of its presence.

' It is apparent" for these reasons that thisform of drill could not be employed for the drilling of deep wells due to its inherentI defects, and that `another form of drill must' be devised if the standard form of drill commonly used in deep well drilling was to be improved upon. It is well known that the standard drill is objectionable on account of/ the fact thatit requires frequent cleaning, and the necessity of frequent cleaning of.

vthe drill tools and bailing of the hole rewha ."these and-other objects in view the l out in connection with the accompanyinwdrawings, in which;

Fig. Lahore a. view in elevation partly in section .o-.t theimproved drill tools at the bottom uit weil;

2 lshows ari-enlarged .view ofthe drillhit looking in the direction oit arrows 2-2 of 1; Y Fg. 3 is a cross sectional view of the drillbit taken on the line 3 3 of Fig. 1;

. Fig. 4 is a cross sectional view-ot the drillbit-taken on the line 4 4 of Fig. 1.

In the drawings the drilling apparatus embodying the. preferred form of the invention', is illustrated in connection with a diagrammatically represented well-,indicated by the nun'1eral2. The drilling apparatus comprises a drill-bit yhaving cutting tedges 6 and 8, as shown.v in Figs. 1 and\2`,.-and a shank or upper part of the 'drill-intl() which has a threaded connection witlnafhollow stem 14, which may be made up ofza number of sections. -Through the inner portion of the shank of the drill-bit is formed apassage 16, which communicates with iutes 18 and 20 thnough passages 22 and 24, as shown in the drawings. The flutes of the drill-bit are provided with eover`plates 26 and 28, which are attached to the drill-bit in such a manner as to form a closed water passage that will deflect the water against the cutting faces 6-8 of the drill-bit. The stem 14 is hollow and may be any convenient length and diameter, depending on the total weight of the drill tool desired for the drilling operation. W'Yithin the stem 14 is a valve housing 3() which is cylindrical in shape andv has the same external diameter as the stem. Immediately above the housing 30 two inlet ports 32 are provided in the stem which open upon a'eentral vertical passage 34 that communicates with the housing. During the downward movement of the drilling apparatus or tools the passage 34 is sealed by a check valve 36. Any suitable t'or/'m ot valve may be used, but in the preferred form ot the invention the valve consists of a spherical ball 3G fitting` against a shoulder .38 in the passage 34 and held in place by a suitably tensioned spring 40. The spring 40 is secured in place by a cage 42, consisting eta base 44 having rour up.

1,57o,sae

` *i consists in the features which willwardl extending arms 48 which serve to holdt e spring during compression in axial alignment, and which assure a rapid and curate seating of the ball valve on its return to the seat after allowing passage of water through t-he valve port. The usual rope socket 50 is secured to the upper end of the stem by which the tool may be attached to the drilling cable.

The operation of the improved type of drill in the drilling of oil wells is as follows: The 'cable which is attached to the drill tool is reciprocated in the ordinary manner by a walking beam or 'spudding arrangement to which it is attached. By the recip'rocation of the cable and tool, the cutting edges of the drill come into contact with the material at the bottom of the )Nell and cut away or loosen the'material therein. During the drilling operation water is supplied to the well hole in the same manner as in ordinaryv drilling operations to assist in the cuttingpand in the removal of loosened material. rlhe same hydrostatic Vconditions are maintained in the operation with this form of drill as are attained in the ordinary drilling operations, but it is essential with this form of drill that the water level. in the well be maintained at a depth above the level of the horizontal passageways 32 when the drill is in its uppermost position. On the upward motion of the drill 10 the liquid contained in the assage is, by reason of its inert-ia, cause to iow downwardly through the outlet portsv 22, 24, and along the iutes 18, 20 to .the space which is occupied by the bit when in its lowermost position. the resulting partial vacuum in 'the upper part of the chamber below the check valve added to the pressure of liquid above the in- At the same time let passage 34 causes the deflection of the ball check valve 36 and causes liquid to iiow into the chamber anddown through .the passage 16. The liquid `Flowing over the cutting faces of the bit removes adhering mud, sand, etc., and prevents the formation of mud pads. On the downward movement of the tools the liquid occupying the bottom of the hole is forcedrupwardly between the tools and the walls oi" the well carrying with it the drill cuttings. During this downward movement the liquid contained in the passage 16 cannot escape upwardly through the tools because of the check valve in the housing 32, and is therefore carried downward with the tools. At the end ot the downward stroke the inertia oit the liquid in the water passages causes it/to continue its downward movement with essentially the same velocity as that of the tools during the y n at themenrdrot the drill-bit into contact with the cutting edges, upwardliy between the tools and the well fwall, and from thence through the openingsl back into the' central passage of the tool. The level of the water in the hole is maintained above the opening 34 inorder to attain the desired circulation, but it is desirable not to have too great a depth of liquid in order to prevent excessive frictionalv resistance. It has been found in the operation of this apparatus that sand and heavier drill cuttings may be suspended in water containlngclay, and

held in suspension for a considerable period' more and more clay is suspended during the course of the circulation and the sludge is better able therefore to hold sand andheavier materials in suspension. The drilling op- .eration may thus be continued for a much longer period than with the ordinary form of drill, on account 4of the manner of circulation to prevent the clogging of the drillbit and to attain thev suspension of drill cuttings. This form of apparatus is therefore admirably adapted forv drilling deep wells where it is desired to drill for as long a time as possible without the necessity of cleaning the tools and bailing the drill hole.

The exterior form or contour of the drillbit is substantially the same as that of the standard drill-bit so as to retain all of the advantageous features of the standard bit. The customary water channels 52 at opposite sides of the bit are retained, thereby providing ample room at the center of the cutting edge for the water t0 pass up between the bit and the well wall, and thus also causing a circulation in the direction from the outer corners of the cutting edge of the bit toward its center and effectively washing the mud away from the cutting edge along its entire length. The cover v plates 26 and 28 over the flutes 18 and 2O maintain substantially the same shape on the bit edge as the edges of the standard The shape and position ofthedrill-bit. cover plates 26 and 28 are important in di recting the bit cleaning water on the cutting faces and edges of the drill-bit to maintain an efficient drilling action.

Various chan es and modicationsof the apparatus may e made without departing from the spirit or scope of the invention.

Having thus described the preferred form of the invention, what I -claim as new is:

1. A drilling apparatus comprising abit having' a cuttingedge extending substantially transverse to' the axis of the bit, vsaid bit having longitudinal channels in the plane' at right angles to the longitudinal plane 1ncluding the cutting edge of said bit, and means4 for providing a downward draft of water at the corners ofsaid cutting edge.

2. A .drilling apparatus comprising a bit having a cutting edge extending substantiallv transverse to the axis of the bit, said bit having' longitudinal channels in the plane at right angles to the longitudinal plane in-A cluding the cutting edge of ,said bit, and means for providing a downward draft of water at the corners of said cutting edge on the upward stroke of the bit only.

3. A drilling apparatus comprising an elongated drill bit having a transverse -cutting edge, longitudinal water channels in f the sides of the bit, longitudinal water passages extendinnr along the edges of thepbit in the longitudlnal plane of the cutting edge of the bit and arranged to conduct water therethrough and discharge itdirectly upon the corners of the cutting edge of the bit, an elongated stem to which the bit is connected, a passage-way connecting with thev said water channels and extending through saldstem, said passage-way having an openlngin the stem positioned a substantial distance above the bit, and a valve mounted in the said passageway arranged to permit downward movement. only of the liquid y through the passageway and channels.-

4. A drilling apparatus comprising' 1n combination a drll -bit having a cutting edge, longitudinal flutes leading to the cut-- ting edge of the said drill-bit, a hollow shank, passageways' connecting the said utes with the said hollow shank, plate deflec'tors covering the said flutes, a hollow stem connected to the said hollow shank, a check valve in said stem permitting downward passage of fluid through the said stem, a passageway tol the inlet side of the said valve communicating with the exterior of the said stem to permit circulation through the apparatus, and longitudinal channels on the side of the bit separated from said flutes.

5. A drilling apparatus comprising an elongated drill bit having la transverse cutting edge, longitudinal water channels in the sides of the bit and longitudinal water passages extending along the ed es ,of the 

